It's now late and my brain may be malfunctioning. I've pulled out an old computer and had a look at calculations where I've given myself a heading, TAS, ground speed and wind drift angle. From these calculations I can calculate the wind direction and speed by using either method. What am I missing? I dare say that this will all seem clearer tomorrow.
I can see that Whopity's answer makes sense. As do BigEndBob's comments about first principles and vector triangles.
Last edited by Esperanza; 25th February 2008 at 21:22.